Temperature-indicating instrument.



- A. N. ozlAs. TEMPERATURE INDIGATING INSTRUMENT.

APPLICATION FILED DEO. 22,'909.

973,963. l Patented oct. 2.5, 1910.

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nizw. fitta-@nui 5 ALBERT N. '0ZIAS, OF MINNEAPOLS, MINNESOTA. i

y TEMPERATURE-INDICATING INSTRUMENT.

Specification of Letters Patent. AppIication led December 22, 1909. Serial No. 534,508.

Patented oct. 25, '1910.

To 17] i/lom 'it muy concern:

y lle it lknown that l.,v Amann'r N. OZIAS, a. citizen of the United States. residing at Minneapolis, in the. county of .llennepin and State, oil.E Minnesota, have invented certain nenv and useful lmlnrovements in 'lemper'ature-indicating Instruments; and I do hereby declare the following to be a full, clear,

4 and exactdescription ot' the same, reference the.',ditl'erenty expansibility of metallic eleliientsfaiitl-is made manifest through the variations .-.between the lengthof an are and its ellordgft-he Aarcbeing that member which isai'lapltwl to. be deflectedintermediate its ends and thel degree oi deflection being controlled bythe chord memberY An instrument of thistype is illustrated in my prior Patent 'No f90-1,558, dated November 24, 1908, and the present invention is an improvement upon the arrangement and construction illustrated in said patent, whereby the instrun'ient` adapted for uses not especially contemplated heretofore and Whereby the. construction is greatly simplified and eheapened. ,Y llteterring' to -the laceompanying drawings'--li`igure-l is a .tace vieiv of an instrument embodying the present improvements;l lfig. 2 is a similar-view with the front plate and-dial removed and a vpart of` the chord v member broken away; Fig. l a sectional view through the casing and showing the working partsin edge elevation; and Fig. 4 is a sectional view through the casing in a plane at right angles to Fig. 3 and showing the working'parts in end' elevation.

Like letters of reference in the several figures indicate the same' parts. The body of the ing i'n whieh'the workin?! Darts of the.instrlu'nentf are mounted' is 4indicated by the letter .it and is preferably in the form of a pressed steel receiver of tion, in a manner rectangular shape with inwardly projecting.

brackets a. secured in its opposite ends. The cover l?) is also of pressed steel with flanges o beaded to give rigidity to the structure and adapted to lit over the side edges of the body A. The cover B is preferably secured in position by screws C passing through the cover and, into the brackets a before referred to. Upon the cover there is formed Ior mounted a dial casing D adapted to contain a quadrant dial or graduated are d, the whole being preferably inelosed by a ,glass cover held 1n place by anannular lange'D, the base of which is adapted to fit tightly around the dial casing and be held by frictune.

The mil-king parts of the instroulent-,embody a chord member which. is struck up from relatively heavy sheet'brass `or other metal having expansion. The body portion F 'of the chord member is of channel or U-form, in crosssection, as indicated in the drawings and has on one side a bracket F, conveniently integral with the chord member and ofthe. same material whereby differential expansion betneen-tbgbracket and chord member is eliminated. The bracket F is provided with a supplemental arm or projection f and bearings-are formed in the supplemental'arm ands'bracket for a pointer or indicator shaft G adapted to project through the casin cover and dial and to earrv on its end a polnterH for registering with the graduations on the dial.

The arovmember is preferablyI infthe form of a` strip or thick ribbon I of Ymetal having a low coefficient of'expansion and. is located Within the. chord member, its ends being securely vanchored to the Iends of said chord member. The form of anchorage preferably adopted and illustrated in the drawings embodies a transverse. anchor pin around which the end of the arc member is secured, the said pinbeing supported in seats or recesses z" in the side walls of the chord member and in proximity to the .base of the' channel. Additional su port may be given acholing pins inturned arms i2 inte al with the base o the chord to 'tt'old 'the same centrally within the channel `tof" the chord member.

conveniently familiar to the arts at this member, althoiig'li` the prunary function of said n'ifurned arms vis to positron the are member or channel of the i The arc member and the chord member are preferably so proportioned with relation to each other that, at. ordiliary tcmperatures, it no deflecting influence be exerted on the are member, it will be substantially straight from end to end and free from lost motion and, as the ten'iperatnre rises it is put under increased tension and its rividity increased proportionatel)r as the length of the chord member increases. In adjusting the instrument, however, the arc member is deflected intermediate its ends by means of a rack bar K pivotally connected therewith, and at its outer end connected with a cil spring li, the opposite end of which is supported by a finger or projection f3 on the bracket I4", The rack bar K meshes with a' pinion on the pointer shaftbctween the bearings in the bracket,` before referred to, thus providing an operating connection between the arc member and the pointer or indicator, whereby the pointer or indicator will be turned in exactI proportion to the elongation of the chord member.

In the preferred construction, the end of the rack bar is passed through an aperture in the arc member and the connection established by a small transverse pin located in rear of the arc member, but it is obvious that otlierknown forms of connection may be employed without departing from the invention.

The spring for imparting the transverse deflection to. the arc member is normally under suicient tension toprovide for moving the pointer to the minimum temperature adapted to be indicated by the instrument and it will be noted that the arrangement is such that any variation due to the expansion and contraction of the s pring itself 1s practcally compensated for by a corresponding expansion and contraction of the' arc member; for instance, a .rise in temperature whereby the spring is elongated and to this extent lts power weakened, is compensated for b a corresponding elongation ofthe areV mem er, thus if no chord memberwere present the pointer would remain practically stationary; as aresult vof this arrangement the only movement-oi' the pointer isydue to the elongation of the chord meinber itself, which clon ation, by straightening the arc member an putting it under increased longitudinal tension, reduces the deflection in proportion to such elongation. The movement of the rack bar is, is well known in such an arrangement, very much greater than "the movement of the ends of the arc member and such movement is further amplified by the em. loyment ofa small pinion and relatively ongpointer.

For the purposes for which the present instrument 1s designed, the augmentation of .the movement through thc means specified is ample forall practical purposes, even where the length of the chord and arc members does not exceed a few inches.

The chord member, together with the parts carried thereby, is convenici'itly held in the casing by being fitted between one oi.' the side walls of the casing and the ends ot the brackets c, which brackets, with the ends of the casing, form seats for the ends of. the chord member and the cover i'or the casing serves to hold said mcnlber in position and to prevent any looseness which might tend to produce inaccuracy in the registration.

Having thus described my invention, what I claim as new and desire to secure by lic-lters Patent of the United States, 'is-- 1. In a temperature indicating instrnn'sent, the combination with a substantially straight and rigid chord men'iber having a li' fh coeiicient of expansion, a deiiectible are mem'- ber having a low coeflicient of expansion rigidly supported at its ends by the Vends of the chord member, a rack bar at one end connected with the are member intermediate its ends, a spring norn'ially under tension connected with the opposite end of said rack ba r, a pinion in mesh with the rack bar, and a pointer operated by said pinion.

2. In a temperature indicating instrument, the combination with a substantially straight rigid chord member having a high coeliicient of expansion and a deflectible arc .member having a. low coeticient of expansion with its ends connected rigidly with the ends of the chord member, of abraoket projecting from 011e side of the chord member, a rack bar connected with the arc member intermediate theendsof the latter, a spring interposed between the rack bar and bracket v and normally under tension tending to Cle-- vtlectthe arc -men'iber, a pinion l{carnale-d in the bracketand in mesh with t 1e rack bar, and a pointer operated by said inion.

3. In an instrument such as escribed, the combination with a substantially straight and rigid chord member of channel form in cross-section, ofA a delectible arc member haring a lo\v coelticient of expansion held under longitudinal tension by being anchored at its ends to the ends of said chord member by transversclly extending supporting pins, and means w iereby arc member may be yieldingly-detiected intermediate its ends, the arrangement being such that, as the ,temperature rises said are member is put under increased longitudinal tension and itsxresistance-to transverse deiiectvion ncreasedj,

4. ln' a temperature indicating instrument, the combina( ion' with the substantially straight rigid chord member of channel form in cross-section, an arc member h aving a relatively low coefficient of expansion,

transverse pins seated in the chord member at the ends and forming the anchors for the arc member, a rack bar connected with the arc member 'intermediate its ends, a spring connected with said rack bar and under tension tending to deflect lthe arc member, a pinion.in mesh with Said rack bar and mounted 'inbearings rigidly connectedvwith the chord member, and a pointer moved by said pinion.

5. In al temperature indicating instrument, the combination with the substantiall straight rigid chord member having a lug .:oeiicient ofjexpansion and of channel form= m cross-section, anchor seats vin the side Walls ofsaidgehord member and a'r'rris 'inf tofsaid side Walls, of an Varc proximit n having al relat-lvely'loiv coeliiclent member of expansion, anchoring pins lto which the ends of saidarc member are secured, mount, ed 1n said seats, the ends ofsald arc member lmsslng between and bemgheldm proper `transverse position by the arms on the chord ing end brackets therein anda cover for said casing, ofthe substantially straight rigid'chord member held in place in said casing by said brackets, an 'arc member having a low ce'eiicient of expansion anchored to the ends of said chord member, and an indicator operatively connected with the arc member lntermedlate its ends.

7.111 a temperature indicating instrunient, the combinationv with the casing, the lSubstantially strai ht rigid chord member having a lngh coe cient of expansion seated in-said casin the arc member having a low coefficient oex ansion anchored atits ends to the ends o the chord member, a spring for deecting the arc member intermediate its ends, an .indicator and operative memberof 'a cover for said casing,l a dial with which the Vmdlcator reglsters, mounted on said cover, and means for connecting the cover and casing, substantially as descrlbed.

, ,ALBERTN OZIAS. -Witnes`ses:

y L. A. .HUBACLUK, .y

'.LiLLm LARsoN. s

lconnections between 'said indicator and arc 

